Reflecting a Shape in the Y-Axis Using Cartesian Coordinates
(KS3, Year 7)
- The point A has Cartesian coordinates (3, 4).
- The reflected point A' has Cartesian coordinates (−3, 4). The y-coordinate is still 4, but the x-coordinate has changed from 3 to −3.
How to Reflect a Shape in the Y-Axis Using Cartesian Coordinates
Reflecting a shape in the y-axis using Cartesian coordinates is easy.Question
Reflect the shape below in the y-axis.Step-by-Step:
1
Find the Cartesian coordinates of each point on the shape.
Write the x-coordinates and y-coordinates of each point.
Point | x-coordinate | y-coordinate |
---|---|---|
A | −3 | 2 |
B | −2 | 5 |
C | −1 | 2 |
2
Find the Cartesian coordinates of the reflected points.
Keep the y-coordinate the same, but change the sign of the x-coordinate.
Point | x-coordinate | y-coordinate | Point | x-coordinate | y-coordinate |
---|---|---|---|---|---|
A | −3 | 2 | A' | 3 | 2 |
B | −2 | 5 | B' | 2 | 5 |
C | −1 | 2 | C' | 1 | 2 |
3
Plot the reflected points and draw in the shape.
Answer:
We have reflected the shape in the y-axis.A Formula to Reflect a Point in the Y-Axis Using Cartesian Coordinates
In general, we write Cartesian coordinates as: x is the x-coordinate. y is the y-coordinate. x and y can taken any number. The reflected point has Cartesian coordinates:The image below shows a general Cartesian coordinate being reflected in the y-axis:
What Is a Reflection?
A reflection flips a shape so that it becomes a mirror image of itself. A reflection is a type of transformation.Worksheet
This test is printable and sendable